JPS62219748A - Contact type image sensor - Google Patents

Abstract

PURPOSE:To prevent contamination due to the contact movement of an original from generating, by providing a projection positioned in parallel with the longitudinal direc tion of an illumination window in the neighborhood of a reading position except the reading position of the original at least, on the upper plane of a transparent protect ing layer. CONSTITUTION:A light shielding layer 3 of Cr is formed on a transparent glass sub strate 1 so as not to irradiate the position except the reading position of an original 2 by illumination light. On the light shielding layer 3, an illumination window 31 formed in a slit shape is provided to introduce the illumination light to the original 2, and a photoelectric transducer string 4 made of CdS or an ampolphous Si, etc., is formed at an insulation layer on the light shielding layer 3 at the one side or both sides of the illumination window 31. A transparent protecting layer 5 of a thin glass plate of about 0.1mm is provided so as to cover the light shielding layer 3 including the illumination window 31 and the photoelectric transducer string 4, and semicylindrical projections 6 made of glass are stuck at both the sides of a line-shaped reading position on the upper plane of the transparent protecting layer 5. In this way, the transparent protecting layer corresponding to the reading position of the original can be prevented from being contaminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contact type image sensor, and more particularly to a contact type image sensor used as a photoelectric conversion device in facsimiles, optical character recognition devices, copying machines, and the like.

[Conventional technology]

Close contact type image 7/SU is MO8 type image 7NSA and CC
Compared to IC image sensors such as D image sensors,
Since a reduction optical system using a lens is not used, a facsimile machine or the like can be made compact and has excellent economic efficiency.

FIG. 2 is a perspective view of an example of a conventional contact type image sensor.

The contact type image sensor shown in FIG. 2 includes a light shielding layer 3 having a slit-shaped illumination window 31 provided on a transparent substrate 11,
A photoelectric conversion element array 4 formed on the upper surface of the light shielding layer 3 and consisting of a plurality of photoelectric conversion elements arranged in parallel along the longitudinal direction of the illumination window 31, and a transparent protective layer 5 provided covering the light shielding layer 3. It consists of:

As shown in FIG. 2, the original 2 to be scanned moves while closely contacting a transparent protective layer 5 made of glass that is provided to cover the light shielding layer 3 on the transparent substrate 1 made of glass.

When irradiated from the bottom surface of the transparent substrate 1 with a rod-shaped light source 7 such as a fluorescent lamp, the light passes through the transparent substrate 1, the illumination window 31 and the transparent protective layer 5 and irradiates the original 2, and the light reflected from the original 2 is removed. The photoelectric conversion element array 4 performs photoelectric conversion and reads the image on the document 2.

With this configuration, the optical path length is shortened without using a lens system, improving the efficiency of light use, and making it possible to downsize and lower the cost of the device.Moreover, recently, polycrystalline Si thin film transistors have been used. Further miniaturization and cost reduction are being achieved by forming the scan drive circuit used on the same substrate.

[Problem that the invention seeks to solve]

In the above-described conventional contact type image sensor, since the document moves while being in close contact with the surface of the transparent protective layer, the light extraction position becomes contaminated due to the transfer of ink on the document and the adhesion of paper fibers. The accuracy of reading a document is normally 8 lines per chicken or 16 pieces per cup, and even if the size of contamination is several tens of micrometers, the light will be blocked and the electric signal will be black, so there will be black on the recording surface. There is a problem in that striped patterns occur and the image quality deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to provide a contact type image sensor that does not cause contamination due to the close movement of a document.

[Means for solving problems]

The contact type image sensor of the present invention is mounted on a transparent substrate.
a light-shielding layer having a slit-shaped illumination window provided in the light-shielding layer; a photoelectric conversion element array in which a plurality of photoelectric conversion elements formed on the light-shielding layer are arranged in parallel along the longitudinal direction of the illumination window; In a contact type image sensor, the contact type image sensor includes a transparent protective layer that is provided to cover the top surface of the transparent protective layer so that the document moves in a direction perpendicular to the longitudinal direction of the illumination window. The illumination window has protrusions provided in parallel with the longitudinal direction of the illumination window in the vicinity of the reading position except for the reading position.

[Effect]

In the present invention, when feeding a document in the feeding direction (sub-scanning direction), in which a protrusion parallel to the illumination window is provided near the document reading position on the transparent protective layer, the document is lightly pressed to the reading position with a rubber roller 2 or the like. wear.

However, with the above configuration, the original comes into contact with the protrusion and does not come into contact with the transparent protective layer at the reading position, so the reading position is not contaminated. Therefore, reliability is achieved without erroneous reading due to contamination. A high-quality contact image sensor can be realized.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of one embodiment of the present invention.

The difference between the embodiment shown in Fig. 1 and the conventional example described above is that protrusions are provided on the transparent protective layer.◇In Fig. 1,
A Cr light shielding layer 3 is formed on a glass transparent substrate 1 so that illumination light does not irradiate areas other than the reading position of a document 2 (in the case of a facsimile machine, this is the main scanning line). When using a metal layer for the light shielding layer 3, SiO□ or S
i, an insulating layer such as N4 is formed. A slit-shaped illumination window 31 is provided in the light-shielding layer 3 to guide irradiation light to the original 2. A photoelectric conversion element array 4 made of CdS, amorphous Si, or the like is formed on an insulating layer on the light shielding layer 3 on one or both sides of the illumination window 31.

The photoelectric conversion element array 4 is constructed of a planar type in which electrodes are taken out from both sides of each photoelectric conversion element, or a sandwich type in which a photoelectric conversion film is sandwiched between upper and lower sides with electrodes. In addition, in the direction in which they are arranged in rows, 8 elements/IEII or 16 elements/W
The reading length is equal to or more than the reading width of the original 2.

Furthermore, the light shielding layer 3 includes the illumination window 31 and the photoelectric conversion element array 4.
A transparent protective layer 5 made of thin glass having a thickness of about 0.1 .mu.m is provided so as to cover it. Semi-cylindrical glass protrusions 6 are bonded to both sides of the linear reading position on the upper surface of the transparent protective layer 5.

The width of the reading position is a value corresponding to the resolution in the moving direction (sub-scanning direction) of the document 2 and is 100 μm or less, and there is no restriction on the position of the protrusion 6 as long as it is in the vicinity of the protrusion 6 except for this width. However, the height and spacing of the protrusions 6 are such that the document 2 is
It is necessary to set it to a value that does not touch the original reading position. Furthermore, in order to prevent deterioration of resolution, it is necessary to keep the distance between the original 2 and the surface of the transparent protective layer 5 at the reading position so as not to exceed several lOμm.

For example, if the diameter of the row 28 is t''30g11, and the distance from the center of the reading position to the protrusion 6''1 is approximately 1.2cm, then the protrusion 6 with a height of 0.05 to 0.1m is used. do it.

In this embodiment, two protrusions 6 are used on the left and right sides of the reading position, but one protrusion 6 may be provided on each side as long as the above-mentioned nine conditions are satisfied.Also, the material η should be made of metal, insulators, etc. In addition, its shape may be a square prism instead of the above-mentioned semicylindrical shape. Further, as a method for forming the film, in addition to adhesion, film formation may be performed by vapor deposition, sputtering, etc., or may be formed by screen printing.

〔Effect of the invention〕

As explained above, the contact image sensor of the present invention has
By providing the protrusions on the top surface of the transparent protective layer, the transparent protective layer corresponding to the reading position of the document can be prevented from being contaminated, which has the effect of improving reliability and maintaining high quality recorded images.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, and Fig. 2 is a perspective view of an example of a conventional contact type image sensor. , 3...
... Light shielding layer, 4... Photoelectric conversion element array, 5.
...Transparent protective layer, 6...Protrusion, 7...
...Light source, 8...a-a, 31...
lighting window 0

Claims (1)

[Claims] a light shielding layer having a slit-shaped illumination window provided on a transparent substrate; a photoelectric conversion element array in which a plurality of photoelectric conversion elements formed on the light shielding layer are arranged in parallel along the longitudinal direction of the illumination window; In a contact image sensor comprising a transparent protective layer provided to cover the light shielding layer and in close contact with the upper surface of the transparent protective layer, the document moves in a direction perpendicular to the longitudinal direction of the illumination window. A contact type image sensor comprising a protrusion provided in parallel with the longitudinal direction of the illumination window in the vicinity of the reading position other than the reading position of the document.